


by the light of your soul

by viklikesfic (v_angelique)



Category: Marvel Cinematic Universe, The Avengers (Marvel Movies)
Genre: Alternate Universe - Soulmates, Bottom Tony Stark, Enthusiastic Consent, Extremis Tony Stark, Humiliation, Insecurity, M/M, Queer History, Romantic Soulmates, Slurs, Soul Bond, Soulmates, Steve Rogers Is a Good Bro, Top Bucky Barnes, Trans Character, Trans Male Character, Trans Tony Stark
Language: English
Status: Completed
Published: 2021-02-05
Updated: 2021-02-05
Packaged: 2021-03-16 21:47:56
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 5,875
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29214408
Author URL: https://archiveofourown.org/users/v_angelique/pseuds/viklikesfic
Summary: “I’m forty-two,” Tony turns to lean back against the counter and gestures vaguely up and down his body as he takes a sip. “Odds are pretty low, Cap.” He doesn’t add that it would be anightmareif he did have a soulmate, because they’d likely be attracted to thewrongversion of himself, to the wrong gender, and Tony isnotwilling to have that conversation. He’s the most famous trans man in the world. He transitioned soon after Howard and Maria died, relieved that no one had given him that spark, trapped in a body that never felt like it fullybelongedto him. He then spent the next sixteen years focused on making superior weapons technology and trying to convince Obidiah Stane to respect him. He hates himself for that.He won’t play girl for his soulmate. He’d sooner die.
Relationships: James "Bucky" Barnes/Tony Stark
Comments: 20
Kudos: 325
Collections: STB Bingo: Round One





	by the light of your soul

**Author's Note:**

> CWs: The really rough stuff is only about ⅓ of the total word count, but does contain: play with a trans person’s factory-installed parts. Humiliation. Rough sex. The t-slur, the f-slur, and both those slurs mashed together as a combo platter. If you want to miss all that, skip the sex scene and scroll down to the aftercare. (Look, I almost just wrote a sweet story with no humiliation, but then my fingers slipped. 🤣 I appreciate all y’all who don’t share my kinks and stick around for the writing, I promise less edgy stuff is coming, including sequels to some of my most-loved stories!) Also a bit of historical language applied to LGBTQ folks that would be inappropriate today.
> 
> Basically, come for the worldbuilding and positive trans representation, stay for the weird porn? 
> 
> Written for the STB Bingo square History. In case it's not obvious, my intention was to include two kinds of "history" in this story: Tony's transition history and the history of queer Brooklyn through Bucky's story.

Tony never once believed he’d have a soulmate.

Most people who are going to get mildly electrocuted by a soul-charge get that shit done by the age of twenty-five, give or take. 20% of the global population never finds a soulmate. (15% find more than one, but that’s another story.) Tony’s further and further from twenty-five each day.

Also, he sees his own soul in an Afghan cave when he’s thirty-eight, and he doesn’t like what he sees. He’s afraid of what his soulmate might look like. 

And then there are other things about Tony that make him  _ certain _ there’s not a soulmate out there for him. So he parties, and he fucks around, and no one ever says much about it until Steve Goddamn Rogers. 

“What about your soulmate?” Steve asks, looking genuinely  _ hurt _ after Tony shamelessly escorts a pair of busty blondes into the elevator—in full view of the kitchen the Avengers are sharing while the upper floors of the Tower are repaired—and then wanders to the coffee maker.

“Don’t have one,” Tony breezily replies, filling his mug nearly to the brim with his back to Steve. Girlfriend, well, he  _ did _ have one of those, but Pepper “needs time” after the destruction of New York and he doesn’t really blame her. He’s been staying in the Tower while she’s in Malibu, and they’ve all kind of haphazardly ended up occupying the space alongside him, Barton after some sort of fight with the Russian mob over an apartment building, Steve after his motorcycle tour of America. Bruce doesn’t have anywhere with both the security and science the Tower can provide him, and Natasha may or may not technically live in her designated suite, no one really knows.

“Bullshit.” Rogers goes from lost puppy to attack dog on a dime, which is a neat party trick. Tony suspects there’s more to the good Captain than meets the eye, but they’ve only known each other for a few months, so he doesn’t yet have all the gory details. 

“I’m forty-two,” Tony turns to lean back against the counter and gestures vaguely up and down his body as he takes a sip. “Odds are pretty low, Cap.” He doesn’t add that it would be a  _ nightmare _ if he did have a soulmate, because they’d likely be attracted to the  _ wrong _ version of himself, to the wrong gender, and Tony is  _ not _ willing to have that conversation. He’s the most famous trans man in the world. He transitioned soon after Howard and Maria died, relieved that no one had given him that spark, trapped in a body that never felt like it fully  _ belonged _ to him. He then spent the next sixteen years focused on making superior weapons technology and trying to convince Obadiah Stane to respect him. He hates himself for that.

He won’t play girl for his soulmate. He’d sooner die.

“I don’t believe that,” Steve says softly, his eyes cast down again as he contemplatively chews his eggs. “I believe that everyone has a soulmate.”

“Right. Catholic.”

“Not just that,” Steve shrugs. “I don’t have a problem with same-sex soulmates. I don’t follow the church on everything.”

“But you do when it comes to everyone having one?”

“I believe it. I know it in my own soul. Everyone has a soulmate, even if they never meet, or meet when they’re ninety.”

“All right, well… sorry Cap, but I’m not actually down to wait till I’m ninety to bang.” Tony grins and throws a sloppy salute before he heads to the elevator and down to his workshop.

~*~

Steve keeps doing it, chastising Tony about his promiscuity. It’s annoying, but not so annoying that it actually bothers him. He’s “on again” with Pepper for a little while, and spends most of his time in Malibu. Steve probably doesn’t approve of their non-bonded relationship, but he likes Pepper, and it’s less scandalous than the typical Stark dalliances with the supermodel of the moment. (Like father, like son, in that regard. Howard’s soulmate died in the war. Fidelity was never a particular concern of his, even though he frequently cautioned his teenage ‘daughter’ “not to be a slut.”)

But then Tony meets Bucky Barnes, and everything changes. Bucky turns himself in to Steve shortly after the disaster at the Triskellion, and the Avengers agree to keep him at the Tower given the lack of other secure options since the fall of SHIELD. Tony himself has also relocated permanently to the renovated Tower, split with Pepper, and reinstated himself as an active Avenger. But he coordinates Barnes’ psychiatric care, deprogramming, and legal defense all without actually meeting the man. He offers the Hulk-proof suite as a secure location for Barnes until the deprogramming is complete and proven effective, and in the meantime he mostly keeps to the penthouse and his workshop—and keeps his hookups away from Steve.

Cap’s two best friends finally meet nearly six months after Barnes comes in. They shake hands and it slices through him, that jolt of electricity, sealing their hands together for a moment. It’s overwhelming, but it doesn’t actually feel like sticking his finger in an electrical outlet, for all the jokes Tony’s made in the past. There’s a sudden rush of some emotion Tony can’t name, paired with a physical shock that’s also in some way  _ warm _ . But then the sensation passes and Barnes looks... concerningly pale. He’s muttering something under his breath, and Steve holds Tony in place with a lifted palm, looking a little wide-eyed at having just witnessed a soul-charge in person. 

“Wait. It’s a therapy thing.” 

Okay, that Tony can understand. He’s read all the files on the man who killed his parents, trying to understand Steve’s side of the story. And their contents are horrific. One of the methods they used, Tony recalls, involved direct application of electricity to the brain. 

Sure enough, a few moments after the shock Barnes stops muttering and lifts his head, blinking rapidly. Then his eyes focus and he looks at Tony, hopeful. And  _ then _ Tony fully grasps what’s happening. He instinctively moves back a few steps with a look on his face like a deer in the headlights, before he catches himself and turns to properly flee.

Steve finds him in the workshop. Tony can’t quite bring himself to lock Steve out. Steve, who knows that Tony’s trans and doesn’t judge him for it, despite his 1920s and 30s upbringing. Steve, who simply added freedom of gender expression to his always-evolving mental communist manifesto when he found out. Tony kind of loves him for it. 

“ _ Tony _ . What are you doing?”

“Not fucking up my life or anyone elses’,” Tony mutters, already pacing the concrete floor.

“By walking out on your soulmate? Tony, he thinks it’s his  _ fault _ . He thinks you don’t want him because he’s broken and he’s a killer and all that bullshit.” Tony almost smiles, because he loves how Steve doesn’t question that it’s bullshit, knows that Tony himself would never have those kinds of prejudices. “I told him that you’re probably just shocked you have a soulmate at your age, and to hold tight for a few minutes. I bought you time. So is that what’s going on? Did you run because you didn’t expect it?”

“No, Steve,” Tony growls, throwing his hands up in the air. He’ll explain it now, because Steve’s the only one who will be able to pass it on to Bucky in the right way. “I didn’t want a soulmate because I  _ knew _ this would happen! I knew I’d be destined for some big, beautiful straight man, and I’m sorry but I’m not that excited about getting bitched out for fucking up his dreamgirl soulmate fantasy with a few aftermarket alterations.”

He expects Steve to look offended, but he actually just looks… puzzled. “ _ Bucky _ ? Bucky’s… not  _ straight _ .”

“...he’s not?” Tony didn’t actually see that one coming. Steve shakes his head slowly from side to side. “Oh. Well… there’s a version I hadn’t accounted for,” he admits cynically. (It’s true: he’d thought for a moment, after Pepper, that maybe his soulmate could be a straight woman, but never a gay man.) “Big beautiful gay man freaked out by the fact that my dick’s actually the latest in Starktech.”

"Well I don't know..." Steve grins after a moment, and Tony stops pacing and just stares at him incredulously. "You're pretty good at technological innovation." 

"You... are you making  _ fun _ of me, Rogers?" Steve just loses it, then, and starts full-out laughing. Tony stands there outraged on principle, with his hands on his hips, but at least this feels familiar. "I am the goddamned best at technological innovation," he mutters as Steve calms himself down. 

"Seriously, Tony. Talk to him." 

"I don't know," Tony hedges, going quiet again. "Usually a guy like me discloses to a guy like him, we get a punch in the face for our troubles. And his punch in the face would actually murder me, so. Safety first." 

"This is going to be the time in your life you decide to actually care about safety?" Steve teases. 

"Fuck off." 

"Talk to him, Stark," Steve pleads, softer, stepping closer to Tony. "I don’t know how he’ll feel about a trans partner—I’ve not even explained the concept to him, we had different categories and words back then—but… give him that much. He’s not going to  _ hurt _ you, he’s your soulmate." 

“And what if he  _ is _ okay with it, then what? Then I’ve just been fucking around for the last twenty-five years and I had a soulmate this whole time. Not a great look.” Tony’s voice is soft, and he’s being brutally honest. He’s pretty sure Steve knows it. Waiting for your soulmate was an almost universal practice in their time.

“Tony. He never cared about that like I did. He wasn’t sure it was possible for him to have a soulmate, you know, being like he is. Queer.” Steve shrugs. “Anyway… you’re his. That means you’re exactly right for him, the way you are right now.” 

“Idealist,” Tony murmurs fondly. “All right, fine, you win. I’ll  _ talk _ to him.”

“That’s all I’m asking.”

~*~

Bucky looks very different now, hunching his shoulders as if he could minimize his impact in Tony’s life by making himself smaller. Tony doesn’t like that at  _ all _ . He gestures for the man to take a seat on a sofa and sits himself down quite close, so that when he tucks his leg up in front of himself, his knee presses against Bucky’s thigh. They’re in the common area, but it’s suspiciously empty, likely JARVIS’s doing. 

“I haven’t even  _ remotely _ waited for you,” Tony admits as an opener. His heart thrums a little with the closeness, which would be frightening given his experience with heart failure, but for the warm haze of calm that being around his soulmate puts him under. He hopes it’s temporary—he can’t really  _ think _ properly like this. “You’ll find that the moment you Google me, so, might as well get that out there.”

“I don’t care about that.” Bucky frowns. “You’re forty-two, Tony. I wouldn’t expect you to wait. I didn’t think I had a soulmate, either.”

“So you didn’t wait?”

“No.”

“Huh.” That’s a little surprising, despite Steve claiming that it’s not a big deal to Bucky, and more than a little attractive. Sure, everyone knows that Bucky Barnes was a flirt, that he took women out dancing, it’s part of the official biographies. But you had to assume he was a virgin, like most people were before the soul-charge in their day. It’s a relief that he’s not. “All right, but… you’re seriously  _ okay _ with it? I don’t even know how to handle that. The way Steve carries on… I always assumed I’d be fucked, if he was right about me having someone.”

“He an’ I are gonna have words, later,” Bucky promises, his eyes narrowing. “But that’s not your concern, sweetheart. And it’s not how I feel.” He places his normal hand on Tony’s knee, slow and cautious. The touch sets off sparks again, but they’re less dramatic than before. “Look… I was an assassin. I killed your  _ parents _ . If you’ll still have me… I’m not gonna freak out that you’ve fucked people, Jesus. I’m honestly more curious how you managed to bed so many normal dames.”

“Oh.” Tony feels a little too warm when Bucky says the word “fucked.” “What do you mean,  _ normal _ ?” He’s a little incredulous, mostly just because he knows  _ Steve’s _ opinion of his bed partners.

“The ones who like men. I mean… I know you’re a man,” Bucky quickly adds. “But not all dames would want to be with one who doesn’t have a… uh….” Bucky clears his throat awkwardly.

“Wait, you  _ know _ ?” Tony exclaims. “That I’m trans?”

Bucky nods, casual as anything. “Sure.”

“Steve said he didn’t tell you. He hasn’t even told you what trans  _ means _ .”

“Well it turns out I can learn things without asking Stevie.” Bucky smirks, and he’s  _ incredibly _ handsome. It’s like Tony forgot to pay attention to that, and now that he’s noticed, he can’t focus on anything else. “Also, your generation didn’t actually invent it, messin’ around with gender. There were a few like you, or the other way ‘round. Performers mostly, but I’m sure some of ‘em got around under our noses. I had my suspicions about one smaller guy who worked at the docks for a while.”

“Okay. Fair play.” Tony swallows, then barrels on with it. “And you’re… are you okay with that? And you’re…  _ interested _ ? I mean, if you’re gay, and we’re soulmates…”

“Of course I’m okay with it. And yeah, I’m interested, if you’re not scared off by how I’ve spent the last seventy-some-odd years. All those alleged sweethearts can’t be wrong.”

Tony laughs out loud, tipping his head back. “Dunno that I’d call them sweethearts, but only about half alleged. I get around.” He licks his lips, and Bucky’s eyes follow the motion. He really doesn’t seem bothered by Tony’s sexual habits, which is hard for Tony to wrap his head around. 

“But really. What’s your secret, with the girls? And… the boys like me? I mean, the ones who like...” He trails off, making a vague crude jerk-off motion, and Tony shrugs.

“My tech is just that good. I do  _ have  _ a dick, it’s just not made from the same stuff yours is. If you don’t get too up close and personal with it, it’s difficult to tell the difference. If it’s just penetration, they can’t tell at all. I’m an engineer  _ and _ the richest trans man in the world. Of course I have a state-of-the-art penis.”

Bucky laughs, but he also looks interested, leaning in a bit with his arm along the back of the sofa, close to Tony’s shoulder. “Does it have functionality?”

“ _ Does _ it have functionality?” Tony scoffs. “Gets hard based on my own physiological data, even channels my own ejaculate so I can use it to come a little.”

“ _ How _ ?” Bucky is clearly delighted.

“Extremis,” Tony explains, without a thought to Bucky’s security clearance. (Should be terrifying. Isn’t.) “Used to be more complicated mechanics, but Extremis took care of the last couple of limitations. They’re nanoparticles, basically, that can live inside your body. They kept my ex-girlfriend alive when she fell from a height that should’ve killed her,” he says, but then swiftly moves on when he realizes the parallels. “Allowed surgeons to get shrapnel out of my chest and rebuilt my sternum and a couple of ribs that had been in the way of a medical device I had implanted for a few years. They can also be used independently to essentially create a missing body part, and only interact with your skin as much as they need to firmly attach.”

“Oh.” Bucky blinks and then looks down at his left arm. 

“It wouldn’t be as strong,” Tony admits, lightly touching the vibranium alloy. “It might not be much of a weapon anymore. But we could make it better.” He smiles, and Bucky leans in suddenly and plants a kiss on him. It’s not perfect—their lips aren’t aligned quite right, and Bucky’s are a little dry. But it’s natural in a way that makes Tony’s bones ache.

~*~

They date for a while. It’s sweet, and Tony gets the feeling it’s nothing like either of their experiences. From what he learns of the bars around the Navy Yard and the bathhouses at Coney Island in the 30s, it wasn’t exactly a scene where you remembered your date’s name in the morning. Bucky would take girls dancing for both fun and appearance’s sake, but the men he just fucked. 

Eventually, though, Tony gets Bucky into his bed. “I have a question,” Bucky says, in the midst of a heavy makeout session with Tony lying on top, Bucky’s hands proprietarily cupping his ass.

“Yes,” Tony says a bit dreamily. Bucky laughs and smacks his ass once, hard enough to sting. Tony hisses and wants more of that. He gives Bucky his best bedroom eyes. 

“It’s not a proposition,” Bucky retorts, for some rude reason still following the plot. “Before, you said about your technology… as long as they don’t get up close and personal.” He rubs a thigh up between Tony’s, as if he’s making sure what he means by “technology” is clear.

“Yeah.” Tony grinds down. “What of it?”

“Does that mean no one’s ever had their mouth on you?” Tony sucks in a breath and nods. “Good. That’s mine,” Bucky declares, and Tony whines high in the back of his throat, not even thinking about it, just rubbing his whole body against Bucky’s, pushing his ass into Bucky’s hands. “I wanna suck your dick, Tony,” Bucky murmurs in his ear.

“Please.”

“Let me have it, then,” Bucky counters, and he flips them with a quick move that leaves Tony breathless and aroused, lying on his back with Bucky’s deft fingers unbuttoning his fly. 

“Oh. Yeah,” Tony agrees, lifting up a bit for a hard, sloppy kiss before Bucky slides down his body. His dick’s half hard, and he gives it a little friendly squeeze at the base, a handy trick that cues Extremis to produce a full erection.

“Oh,” Bucky exhales, watching it with greed in his expression. He licks his lips. “You coulda let me do the work.”

“Next time,” Tony laughs. “Trust me, I’m ready.”

“Yeah, all right.” Bucky bats Tony’s hand away and holds it in his own fist (the  _ metal _ one, which shouldn’t be hot but definitely is). His tongue plays over the head, and Tony can’t quite feel it, but it’s still bloody hot. It’s not all the unyielding stiffness of Extremis—the skin under Bucky’s tongue is an outer layer designed to mimic human skin insofar as it’s possible. Coarse dark hair hides how it joins to his real skin, grafted over the edges. It’s not perfect, but it’s better than what plastic surgery can provide. 

Bucky isn’t shy in getting his mouth around it, getting Tony wet, and the visual is definitely a trip. His hair falls into his face, and he sucks dick like he knows what he’s doing, with both finesse and enthusiasm. Tony’s already thinking about how he can reprogram the Extremis that makes his erections possible to register a sucking sensation, maybe pull a bit on his own tissue in response. It’s more subtle than fucking, when the overall pressure and movement provides more than enough to stimulate him to orgasm. But the sheer  _ fact _ that someone is sucking his dick is a huge headtrip, and arousing on its own. Tony runs his hands through Bucky’s hair, encouraging, but doesn’t pull, not sure what might set the Soldier off. 

And then Bucky goes all the way down, sucking Tony into his  _ throat, _ and that’s incredibly hot as well as more physically stimulating, so much so that Tony turns bright red when he realizes Bucky’s chin is glistening. 

“Sorry,” he gasps, wiping it off with the bedsheet when Bucky comes up for air. “I didn’t, uh… fuck. Is this really weird for you?” Tony asks, feeling tremendously exposed and wishing he could do something about that. “It must be, if you don’t fuck women… I could get something to…”

“Tony,” Bucky cuts in quickly, pressing his entire metal hand over Tony’s mouth. It smells like his own arousal. “You’re not a woman. I’m not confused about that.” Then he reaches down with the fingers of his other hand and trails them straight down the line of Tony’s labia, through a slit that’s already dripping. “Here’s what I see,” he murmurs, lifting his hand and  _ sucking _ on each finger, one by one, as Tony stares in shocked, wide-eyed arousal. “I see a body that makes its own lubrication for me, so that I can rub it all over your cock.”

“Oh,” Tony whispers, and feels another flood between his legs. He’s always produced plenty where that came from, part of why he never wanted anyone’s face down there. But somehow with a few words from Bucky, it’s all right. 

“Always wondered if there was a man for me,” Bucky admits, leaning up to whisper in Tony’s ear as he indeed dips his fingers in again and spreads Tony’s own fluids all over his cock. “Used to be different… the boys who wanted to get fucked dressed up like girls, and occasionally they found their soulmates in the men who went looking for trade, but I wasn’t looking for a girl. I wanted someone masculine… who still wanted to take my dick and would ask pretty for it,” he confesses, jacking Tony slowly with a loose fist. “Someone who wanted it real rough. Turns out I just had to wait for a different century,” he teases, and Tony kisses him hard. 

“Do you want to fuck me?” he gasps. It’s not Tony’s only poison, but yeah, he’s bottomed for men before, and he’s liked it. Some of his deepest, darkest fantasies hit that spot. 

Bucky laughs. “ _ Do _ I?” He keeps his hand on Tony’s dick, but nudges Tony’s hips up so that he can grind against Tony’s asshole, even with his package still all wrapped up. “He’s the thing about you. You’re an  _ extra _ dirty faggot, aren’t you?” he whispers in Tony’s ear, and Tony half wonders where Bucky learned modern terminology, while simultaneously caught up in how much the taboo language turns him on. “I mean… you’ve got  _ three  _ holes for a man to fuck. What could be more queer than that?” His thumb brushes below Tony’s cock, skimming over his cunt lips, and he shudders.

“Fucking hell…”

“Do you like that?” Tony nods frantic agreement. “Yeah. You like being my sweet little trannyfag,” Bucky whispers in his ear. Tony feels like he should probably clarify at some point that whatever Internet research Bucky’s done to learn this kind of language should  _ not _ be applied outside of a very narrow context. But also, here is his soulmate, who somehow  _ knows _ some of Tony’s darkest fantasies, and he’s too wrapped up in that to care.

“Goddamn,” Tony gasps. “The mouth on you.”

“All yours,” Bucky promises. “My mouth… the rest of me.”

It’s sweet, but Tony sucks at romance, so he just kisses Bucky and reaches down to palm his cock. 

“Where do you want it? Which hole?” Bucky murmurs against his mouth. He’s stroking Tony’s asshole with his fingers as he says it, and Tony shudders. It’s not something he ever thought he’d share, this kind of full access to his body, but...

“Dealer’s choice,” he rasps. Bucky smiles and it’s a bit evil.

“The dealer doesn’t want to choose. But I’ll dip it in this puddle you made for me first.” Tony shivers and Bucky is giving him a knowing look. He gets his dick out and guides Tony’s legs down, so his hips are propped up against Bucky’s thighs and his legs are stretched out on either side. Then he slaps Tony right in the pussy with his cock, a girthy thing with a fat mushroom cap of a cockhead like a cherry on Tony’s sundae. “That’s my good boy,” Bucky teases, and Tony gasps and jerks when he does it again,  _ so _ turned on, his dick jutting up against his stomach at maximum extension. “Like the way you leak for me.” He keeps doing it, slapping Tony in the pussy and making more fluid trickle out of his body. It’s humiliating and it hits something  _ deep _ inside him, something that no one else has ever really touched. It’s been so many years since he’s been fucked like this, since he still was attempting to exist as a woman (even then, he used a strap-on more often than not), but that doesn’t mean there wasn’t a part of him that still  _ wanted _ it. He shouts and the soulbond crackles with activity as Bucky shoves his dick in.

  
Tony’s not sure why he ever compared it to being electrocuted. It makes his whole body  _ yearn _ and then crest with satisfaction like he’s locked into place, like he’s found his missing piece. Yes, it’s a kind of spark, but otherwise indescribable. 

He snaps into motion, his legs wrapping around Bucky’s waist even as he gasps, as his back arches, as his head falls back. He impales himself and feels the sharp shock of tissues being stretched too quickly, but then he absolutely  _ gushes _ around Bucky’s cock when the other man lifts his hips up, levers higher on his knees, and then pounds right into Tony’s g-spot. He gasps and lifts his legs higher, fucked into babbling senselessly.

“Fuck, oh God, fuck, please,  _ give _ it to me. Give me that dick, Barnes, Jesus.”

“Is that what you call me?”

“ _ Soldier _ ,” Tony gasps, then, a promise and a challenge. It’s intentional that he uses that, not Sargeant. He knows Bucky has dark places. He’s right here, exposing his own. Bucky fucks into him like he’s acknowledging it, Tony’s upper body flat on the bed and helpless as Bucky lifts his hips higher and utterly nails him. 

“Are you gonna be my little bitch, boy? Let me wreck your asshole now that I’ve got my dick wet? Suck it clean after?”

Tony gasps and nods and his air is coming a little short, but he doesn’t care. This is fucking  _ transcendantal _ . He owes Rogers an apple pie for every time he made fun of the idea of him finding a soulbond. 

“Did you worry I’d know, when I met you?” Bucky asks. Tony frowns, thinking  _ that you were a girl  _ is coming next. He cocks his head to the side in question. “That you’re such a sweet, greedy little faggot,” Bucky clarifies, and Tony’s whole body jerks. 

“Please, Soldier. Fuck your bitch,” Tony whispers, barely audible, but of course Bucky hears. He snarls and bears down and fucks so hard that Tony comes from it, squirting into the thin tube aligned with his urethra so that the fluid ultimately drips from the tip of his cock. Then Bucky slips out before he can even get his bearings and flips him onto his stomach. 

Tony grabs a couple of pillows, stuffs them under himself to support his weak chest, and whimpers when the head of Bucky’s cock presses up against his asshole, slick with his own fluids but nothing else. The crazy thing is, he doesn’t  _ want _ prep. He wants not to be able to  _ walk _ after Bucky’s done with him, and it’s like Bucky knows it somehow. The slow persistent stretch is painful, but not completely unmanageable, and Tony groans into his forearm as their bond crackles and burns with the mutual arousal. The trust is bone-deep. He has no doubt that Bucky would stop the moment Tony asked him to, but he doesn’t ask. 

“You didn’t have to keep your pussy, did you?” Bucky asks when he’s halfway in, not even sounding out of breath. His fingers are leaving bruises on Tony’s hips, and it’s all  _ so _ unfair. He loves it.

“I guess not.”

“You could’ve made yourself a pair of balls,” Bucky theorizes, rocking back an inch and then forward, coaxing Tony to open deeper for him. “If you had the technology to make a cock. But you didn’t. You kept your pussy. Did you…” Bucky pauses for just a second, a sharp inhale as he bottoms out, but Tony counts it as a victory in breaking the Soldier’s composure. “...know you wanted to get fucked like this?” He holds Tony’s hips up, relieving the pressure on his chest, and starts to thrust, his balls slapping against Tony’s cunt. It’s humiliating and brilliant. 

“Yeah,” Tony whispers. “I think… I think that’s why we’re soulmates,” he admits, and it’s strangely romantic as thoughts go. “It’s my fantasy.” He breaks off to groan.

“Taking it in the cunt?”

“From a hot, jacked cis guy, yeah. Without it being…” Tony gasps, can’t speak for a few seconds as he adjusts to Bucky increasing the length of his strokes, fucking in hard. It reverberates throughout his whole lower half, jostling his pussy and his clit inside his still half-hard prosthetic cock. It makes his belly leap and his thighs tense up. “...you know. Straight.”

“Sweetheart, you could never be straight,” Bucky says, and it’s so deadpan that Tony bursts into laughter, then shouts when Bucky drills deep into him in response to his sudden relaxation. 

“ _ Fuck _ ,” Tony moans, letting his torso drape over the pillows without any effort, Bucky holding his weight up by points of delicious pain around his hips. The metal hand is reasonably warm against his skin, but it’s still alien enough to make his dick twitch. “I just didn’t… it’s a fetish, not…  _ fuck _ … not a requirement. I didn’t think there was a cis man out there who would do this to me and still…”

He trails off, and Bucky suddenly yanks him up, jolting him forward on his knees so that he’s kneeling up on the pillows to compensate for the height difference, Bucky’s cock balls-deep in his ass. He forms a bar with his arm across Tony’s chest, clasps Tony’s bicep with his metal hand, and rolls his hips in a slow grind that makes Tony shake. “...love you?” he whispers in Tony’s ear, and Tony bites his lip so hard he tastes blood. His muscles tense, but Bucky doesn’t stop fucking him. “We’re soulmates, sweetheart. It’s written in our bones, they used to say.”

Tony’s eyes are watering, and he’s at least 60% sure it’s just from the pain and exhaustion. 40%. 24%. “I didn’t think anyone would… believe that I’m a man. After they played with my cunt.” It’s kind of shocking how certain he is that Bucky  _ does _ believe that, despite the fact that they’re not even done here. The bond pulses in his core.

Or maybe that’s Bucky’s dick.

“Of course you’re a man,” Bucky rasps, his hand splayed on Tony’s hip to brace him for a few harder thrusts. “We covered this. You’re my sweet little faggot, aren’t you? The sweet little faggot I’ve been looking for?” 

Tony opens his mouth to answer, but Bucky quickly shifts his metal hand up and holds Tony’s throat. His finger and thumb unerringly find the spots to squeeze, but  _ just  _ hard enough. There’s no real fear in Tony’s veins as he loses his air, just lust. He makes a little choking sound when the desire to breathe starts to rise up in him, and Bucky grunts and shoves deep up inside him, flooding his ass. He’d like to believe he would’ve insisted on a condom, if it weren’t for the serum. He’d like to pretend he even  _ thought _ about it for half a second. 

Bucky pulls out carefully and helps Tony shift onto his back, up against the pillows, before he crawls up after him and offers the sticky head of his cock to Tony’s lips. He knows exactly where that’s been, and it’s kind of nasty, but he licks it clean anyway. He tastes musk and his own fluids and the salty flavor of Bucky’s spend. Then Bucky snuggles down, pulling up the duvet, and pulls Tony into his arms. That’s the most surprising part. Even after all…  _ this _ … Bucky’s a cuddle bug. Tony’s undeniably charmed.

He nuzzles into Bucky’s chest, enjoys having the bigger man’s arms around him, grinding his cock lazily against Bucky’s thigh considering asking for a handjob and a second orgasm, and then Bucky mutters into his hair. “Wait a minute.”

“What?”

Tony looks up, and Bucky’s staring accusingly at his own arm. “...are you so good with repairing my arm because you practiced on your  _ dick _ ?”

Tony can’t help but laugh, somewhat uncontrollably for at least thirty seconds. “I’ve practiced on lots of things!”

“...that’s not helping your argument.”

“ _ Weapony _ … things.” 

“My arm is a weapony thing,” Bucky murmurs, a simple statement, and Tony wants to kick himself.

“Your arm is attached to your body,” he quickly corrects. “So no, it’s not similar to a weapon, but it’s made of metal and engineered, is my point.”

“My arm is attached to my body,” Bucky suddenly grins, “like your dick!”

Tony groans. “I hate you. You’re worse of a little shit that Steve.”

“I’m really  _ not _ ,” Bucky objects fondly, holding Tony wrapped in both arms again.

“Maybe it’s a tie,” Tony concedes. “Anyway, I’m not good with your arm just because of my dick. Though… I am kind of inspired by the sensory connections. If I could get direct  _ feeling  _ wherever Extremis is…” 

“I’ll give you feeling,” Bucky murmurs, and Tony shivers at the threat in his tone.

“You know,” he whispers to Bucky’s chest after a few minutes of lying there in silence, listening to each other’s breathing. “I always thought my soulmate would have to be… something dark. I don’t have a pure, clean soul. Never have.” He smirks into the scarred skin. “I figured it would be a villain of some kind, a criminal, I don’t know.”

“An assassin?” Bucky gently suggests.

“Nah,” Tony immediately dismisses the implication. “You’re not evil. That’s not what it is. It’s… you know, I always knew there was this thing in me. I didn’t want anyone to really…  _ see _ it. I didn’t want it reflected back at me. I thought maybe I’d have a soulmate who would manipulate me, who would convince me to de-transition, maybe, or just humiliate me and make me feel shit about it.” Tony frowns. “I didn’t think… that maybe the other half of my soul would be dark the way I’m dark. That it would be someone who wrestles with their own demons, not… I don’t know… a sort of awful that I deserve.” He trails his fingers over Bucky’s chest. “I never thought someone might get off on what I get off on, but not… think less of me outside the bedroom.”

“Sounds like you never thought a lot of things, sweetheart,” Bucky murmurs, but it’s not unkind. He strokes his fingers through Tony’s hair, and when his hand rests on the back of Tony’s neck Tony feels like he can finally breathe.   
  


**Author's Note:**

> Should the 15% literally be another story? As in, do you want a polyamorous soulbond story, and if so, which three or more people do you want?


End file.
